Electric switch



C. H. BAYER ELECTRIC SWITCH Filed NOV. 14, 1942 March 28, 1944.

Z Wim Inventor:

Chaes H. Bayer; by Wap/'f6'. is

2 n., 3 IEE;

Atto'rn ey.

Patented Mar. 28, 1944 ELECTRIC SWITCH Charles H. Bayer,

New York Wynnewood, Pa., assigner to General Electric Company,

a. corporation o! Application November 14, 1942, serial 10.465548 s claims. (o1. zoo-169) My invention relates to improvements in electric switches and more particularly disconnecting switches and stop mechanisms for such switches.

It is frequently necessary or desirable to mount a double-throw disconnecting switch so that the movable blade swings in a vertical plane between its closed circuit positions. Of course, there is no danger of the blade moving into the upper closed Y circuit position against the bias of gravity. However, if the switch is open, there is a tendency for the blade lto swing closed under the bias of gravity into the lower closed circuit position. This can readily create a hazard through the unintentional or undesired energization of a circuit when, for example, someone is working on the circuit. Also, the closure of the switch to complete a circuit is liable to result in danger to the switch itself. In order to prevent this false closing, stops have been provided positively to hold the blade at some position intermediate the two circuit closed positions so that the blade cannot swing into the lower closed circuit position under the bias of gravity. Stops with which I am familiar have required special construction of the blade hinge, material modification of the blade structure or the stops have been relatively `complicated and costly.

An object of my invention is to provide for disconnecting switches an improved blade stop attachment which, in one direction of motion of the blade, automatically stops the blade at a predetermined position from which it can be moved further in the same direction only by an operator after the performance of an additional operation to release the stop action. Another :f

object of my invention is to provide a self-resetting stop attachment which is always ready to function in the desired stopping position. A further object of my invention is to provide a simple stop attachment which requires the minimum modification or change of switch structure. A still further object of my invention is to provide for disconnecting switches a blade stop attachment which is equally applicable to single and double throw disconnecting switches of n either the front or back connected types, mounted on either insulators or a flat base. These and other objects of my invention will hereinafter appear in more detail.

My invention will be better understood from 'i the following description when considered in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

Fig. l is a vertical side elevation of a frontconnected single-pole, double-throw disconnecting switch embodying my invention, the blade being shown in the upper closed circuit position; Fig. 2 is a view similar to Fig. 1 to an enlarged scale showing the switch structure at the hinge post and a stop attachment embodying my invention partly in section and with parts broken away. Fig. 3 is a view similar to Fig. 2 showing the blade held in the intermediate or ninety degree position by the stop attachment which is shown partly in section and with parts broken. away. Fig. 4 is a View similar to Fig. 3 illustrating the release of the stop attachment preliminary to moving the blade to the lower closed circuit position. Fig. 5 is a section on the line 5-5 of Fig. 3 showing the fastening of the stop'attachment to the switch blade, and Fig. 6 is a sectionalview to an enlarged scale of another Aarrangement for securing the stop attachment to the switch blade. The single-pole front-connected double-throw disconnecting switch, illustrated in Fig. 1, comprises an electric current conducting member or blade structure which, as shown, includes two parallel-spaced at blade members I0, suitably pivoted at II on a hinge post I2. This post, which is suitably mounted on an insulator I3, is provided with a terminal portion I4. Insulators I5 and I6 on opposite sides of the insulator I3 support tongue contacts I'I and I8, respectively, which are engageable by the blades I0 in the upper and lower throw or closed circuit positions, respectively. The tongue contacts I'I and I8 are provided with terminal portions I9 and 20, respectively. For opening the switch, there is indicated the usual switch hook 2l, which is insertable in 'an openingor eye 22 provided in an extension 23` secured to the free end of the blades I0..

Y In order automatically4 to Istop and hold the blade structure II'I, I0 in apredetermined position intermediate the .upper and lower closed circuit positions when the blade is turned in a predetermined direction, clockwise as shown in Figs. 1 to 4, inclusive, and yet. have it possible to free the blade structure for further movement to the lower closed circuit position and freely to turn the blade in the reverse direction, I provide a relatively simple and economical blade stop attachment 24 which, in accordance with my invention, can be rigidly secured in position on the blade structure by a single holding means 25. The intermediate position shown in the drawing is the ninety degree position indicated by the dotted line position 26 of the blades shown in Fig. l and in full line in Figs. 3 and 4.

tion 30 which engages one surface of the blade structure, as shown more clearly in Figs. and 6. When the :blade structure is of the multiple blade type, the tongue 30 extends between the blades IU, but is rigidly secured to only one of the blades so that the desired freedom of move? ment of the blades to producey satisfactory Ycontact operation is not elimina-ted. As shown lin Fig. 5, the latch support 21 is secured to the left-hand blade |0 by the holding-means 25 which, as shown, comprises a cap'screw 25. This screw passes through an opening in the left-hand blade' I0 and screws into a threaded opening in the tongue 30 and may project into an opening 3| in the right-hand blade i0. For this arrangement, a suitable lock washer 32 is preferably provided. It will be noted that with this arrangement the housing 21 is rigidly maintained in position on the blades by a single screwthreaded device which requires merely the drilling of a single hole in the blade. Where the bladev structure includes twol spaced blades. the support 21 is, in general, of a T-shaped crosssection with an additional surface 33 in engagement with the upper edge 33a of the right-hand blade Ibut not so tightly as to prevent the desired freedom of movement of theblades relatively to each other.

Mounted on the latch support 21 for limited movement in a direction substantially parallel to one edge of the switch blades so as to overlap the hinge element |2 in the intermediate pcsition,` as shown in Fig. 3, is a latch 34. This has .i

a rounded nose portion 35 which directly engages the upper edge o1 the hinge element I2. In order to have the latch 34 move automatically to the stop position as the blade structure Hl is swung from the upper closed circuit position to the ninety degree positionY shown in Fig. 3, the latch 34 is biased by suitable means, such as a spring 35, to move outwardly from the housing or from right to left as viewed in Fig. 3. Since this latch movement must be limited in order that Ythe blade may be freely swung from the ninety degree position back to the upper closed circuit position, I provide a motion controlling and limiting means which, as shown, comprises a crank 31. This crank is mounted on a shaft 38 supported in the housing 21. The arm 39 of this crank iits in an opening in the latch 34 and engages a bearing member 40 mounted on the latch. The other arm 4| of the crank 31 is provided with a projection -42 which comes to rest against a shoulder 43 on the housing 21 to limit the outward movement ofthe latch 34. The outward movement of the latch 34 is so limited that in moving the blade structure ID, l IJ' counterclockwise from the lower closed lcircuit position and lfrom the position shown in Fig. 3 to the position shown in Figs. 1 and 2, the latch 34 prelsents no interference to the movement of the blade beyond that Vnecessary to compress the v spring 38.

VIn order to release the latch from the holding position shown in Fig. 3 so that the blade structure I8, Ill'can be moved from the intermedi-ate or ninety degree position to the lower closed circuit position, the shaft 38 onwhich the crank 31 is mounted is provided with an operating crank 44 having an opening 45 in which the switch hook 2| can be inserted so as to rotate the shaft 38 counterclockwise and thus retract the latch 34 to the nonholding position shown in Fig. 4. Further pull on the switch hook 2| then rotates the switch blades lll, l clockwise from the position shown in Fig. 4. Since the latch then bears against the outer edge of the hinge post 2, it will then be prevented from moving into a holding position. The switch hook 2| may then be removed irom the opening 45 and inserted in the opening 22 to swing the blade into the lower closed circuit position, indicated by the dotted lines 46 Ifitl is desired to swing the switch blades from the lower closed circuit position to the ninety degree position or to the upper closed circuit position, this may be accomplished by inserting the hook 2| in the blade opening 22 and turning the blade counterclockwise about its pivotal support i If it is desired to leave the switch blade in the ninety degree position, then in this counterclockwise movement when the ninety degree position is reached, the latch 34 automatically slides into the holding position shown in Fig. 3 where the latch portion 35 of the latch 3d can slide over the upper edge of the hinge post I2, as shown in Fig. 3.

In order more securely to maintain the latch ysupport 21 in position on the blade structure,

I may use the holding means shown in Fig. 6. As therein shown, this holding means comprises a flat-headed screw 41 which is inserted'into the tongue 30 of the support 21. This screw projects through an opening in the left-hand blade IU. A washer 4B and a nut 49 threaded onto the screw 41 serve to complete the holding action. Inorder to prevent any ready removal of the stop attachment from the blade structure, I further provide a nut locking screw 50 of the self-threading type which, when it is once hammered into position, can be removed only by drilling or destruction cf the parts which it serves to fasten. With this arrangement, assuming the registering holes in the blades iii, Ill are smaller than the head of the screw 41, it is necessary that the latch support 21 be secured to one of the blades 'before they are assembled together and to' the tion in considerable detail,A I do not desire to be limited to the exact arrangements shown, but seek to cover in the appended claims all those modications that fall within the true spirit and scope of my invention. v

What I claim as new and desire to secure vby Letters Patent of the United states is:

l. Means for limiting the amount of angular movement in one direction of the hinged blade of a disconnecting switch comprising a latch support having two angularly disposed faces in eligagement with two similarly angularly disposed faces of the switch blade, means projecting through said support and the switch blade for rigidly securing each to the other, a latch mounted on said latch support for limited movement in a direction to overlap the switch blade hinge when the blade is moved in one direction a predetermined amount from a closed circuit position to prevent further movement of the blade in said one direction, and means for effecting said move- 'ment of said latch.

2. Means for preventing the blade of a vertically mounted double-throw hinged knife-blade switch from falling into the' lower throw circuit closed position comprising a latch support having two angularly disposed faces in engagement with two similarly angularly disposed faces of the switch blade, means projecting through said support and the switch blade for rigidly securing each to the other, a latch mounted on said latch support for limited movement in a direction substantially parallel to one edge of the switch blade and to overlap the switch blade hinge when the blade is moved substantially ninety degrees from the upper throw circuit closed position to prevent movement of the blade to the lower throw circuit closed position, means for elfecting said movement of said latch, and means adapted to be operated to retract said latch and to turn the switch blade toward the lower throw circuit closed position.

3. In a stop attachment for an electric switch having a ilat hinge element and a movable electric current conducting member comprising two substantially parallel spaced blades pivotally mounted on said element against opposite faces thereof, a latch support resting on said blades and having a tongue extending between the blades and engaging only one of the blades, a single holding means for maintaining said latch support rigidly in position on said one blade, a latch mounted on said support for translatory movement in a direction parallel to the edge of said blades, means for moving said latch to project over one edge of said hinge element when the hinge element and blades are in a substantially straight line to prevent turning of the blade member in one direction, and means adapted to be operated to retract said latch and to turn said blade in said direction from said predetermined angular position.

4. In a stop attachment for an electric switch having a flat hinge element and a flat blade member pivotally mounted thereon, a latch support having two angularly disposed faces in engagement with two similarly angularly disposed faces of the switch blade member, a single holding means for maintaining said latch support rigidly in position on said blade member, a latch housed in said latch support and longitudinally movable therein, said latch having a portion engageable with one edge of said hinge element when said blade member is at a predetermined angle with the hinge element, means biasing said latch into said engagement whereby to cause the latch to overlap the hinge element when the blade member and the hinge element are at said predetermined angle to prevent turning of the blade member in one direction, and means adapted to be operated to retract said latch and to turn said blade in said direction from said predetermined angular position.

5. In a stop attachment for. an electric switch having a flat hinge element and a nat bar blade member so pivotally mounted on the hinge element that one edge of the member and one edge of the element are in alignment when the blade member is moved substantially ninety degrees from the closed circuit position, a latch support positioned on said one edge of the blade member and against a face thereof, means projecting through said support and said blade member for rigidly securing each to the other, a latch mounted on said latch support for movement in a direction substantially parallel to saidl one blade member edge and to overlap said one hinge element edge when said edges are in alignment whereby to prevent turning the blade member in one direction, means for effecting said movement of said latch, and means adapted to be operated to retract said latch and to turn said blade in said direction from said predetermined angular position.

6. In a stop attachment for a vertically mounted double-throw disconnecting switch having a flat hinge element and a movable electric current conducting member comprising two substantially parallel spaced blades pivotally mounted on said element against opposite faces thereof, a latch support seated on adjacent edges of said blades and having a tongue extending between the blades and engaging only one of the blades, a single holding means for maintaining said latch support rigidly in position on said one blade, a latch mounted on said latch support for limited movement in a direction substantially parallel to said adjacent switch edges and to overlap said hinge element when the conducting member is moved substantially ninety degrees from the upper throw circuit closed position to prevent movement of the member to the lower throw circuit closed pc-sition, means for effecting said movement of said latch, and means adapted to be operated to retract said latch and to turn the conducting member toward the lower throw circuit closed position.

'7. In a stop attachment for an electric switch having a hinge element and a blade element so pivotally mounted on the hinge element that a surface of the hinge element and a surface of the blade element are in alignment when the blade element is in a predetermined open position, a latch mounted on said blade element and biased for movement parallel to said surface of the blade element and along said surface of the hinge element when these surfaces are in alignment.

8. In a stop attachment for an electric switch having a hinge element and a blade element so pivotally mounted on the hinge element that a surface of the hinge element and a surface of the blade element are in alignment when the blade element is in a predetermined open position, a latch mounted on said blade element and biased for movement parallel to said surface of the blade element and along said surface of the hinge element when these surfaces are in alignment, and operable means for moving said latch against said bias.

CHARLES H. BAYER. 

